Jupiter is the fifth planet from the Sun. Jupiter is the largest planet in the solar system. Jupiter is the fourth brightest object in Earth's sky. The Sun is the brightest followed by the Moon and Venus. Jupiter is more than three times brighter than Sirius, the brightest star. Due to its prominence in the sky, the Romans named the planet for their chief god, Jupiter. Jupiter has a pearly color with bands of pastel browns and blues. Reta Beebe (2000) states Jupiter emits strong radio waves at many frequencies. Jupiter has a magnetic field that is, a surrounding area of magnetic force. Jupiter acts like a giant magnet Jupiter's orbit of the Sun at is an average distance of 480 million miles. This orbit is about five times the distance from the Earth to the Sun. Jupiter's year, or the time it takes to complete an orbit about the Sun, is equal to approximately twelve Earth years. Jupiter's day, or the time it takes to rotate on its axis, is about 9.9 hours, which is less than half an Earth day.
McKay, Hill, Buckler, and Ebrey, (2000) states in 1610, Italian philosopher and scientist Galileo Galilei conducted the first telescopic study of Jupiter and documented his findings in Siderus Nuncius. The commonly held view of the universe was one developed by 2nd-century Alexandrian astronomer Ptolemy. Ptolemy's model assumed that all of the stars and planets moved in orbits around Earth. This is known as the geocentric view of the solar system. Galileo discovered four satellites, or moons, revolving around Jupiter, and this discovery became the evidence, which supported the competing Copernican theory. This theory, known as the heliocentric view proposed by Polish astronomer Nicolaus Copernicus in the early 1500s. Copernicus held that the planets, including Earth, revolve around the Sun. Galileo strongly supported the Copernican model and played a major role in advancing this theory and creating a more modern view of the solar system.